Development and performance of a piezoelectric energy conversion structure applied in pavement

•An energy conversion structure is designed to make it co-vibrate with road traffic.•The structural parameters are defined to improve power efficiency and durability.•The power performance and durability are studied to meet the requirements of road applications. This paper presents a multi-layer cantilever piezoelectric energy conversion structure for pavement, which avoids weakening the electrical output after the mass contact and realizes the coordinated vibration of each cantilever piezoelectric energy harvester and road driving. In order to ensure the structure meets the requirements of power generation and durability when applied in road engineering, based on the power generation theory of energy harvester, the structural parameters related to the electrical output magnitude are clarified. Based on the power generation performance and durability of energy conversion structure under typical road traffic characteristics, the optimal cantilever position and vibration amplitude are determined, which lay the foundation for the development and application of energy harvester in road field. The results indicate that the improved structure has the best power generation performance and durability with the condition of the distance from the piezoelectric material to the fixed end of 7 mm and the vibration amplitude of 4 mm under under typical road traffic conditions. The output voltage of the monolithic energy harvester at 5 Hz vibration frequency is 5.2 V, the output power can reach 3.14 mW, and the power density is 0.0063 mW/mm3. This power level and power density are significantly higher than other mechanisms. The structure will make it possible to co-vibrate with the driving, and the structural parameters avoid the misunderstandings of traditional designs that only the power generation performance is valued and the durability can be ignored, which make the structure can be used for collecting electric energy in pavement.